Stabilized motor fuel



Patented ay 9, l9

are

STABILIZED MOB FUEL Everett E. Gilbert, Elizabeth, N. 3., assignor to Tide Water Associated Oil Company,

Bayonne,

N. 3., a corporation of Delaware No Drawing. Application March 28, 1941,

' Serial No. 385,695

6 Claims. (01. 44 -74) The present invention relates to antioxidants for use in inhibiting the development of gums in gasolines and to compositions comprising gasolines normaily tending to form gums in the presence of air, as when in storage, having incorporated therewith such antioxidants.

The invention derives fromthe discovery that certain alkyl substituted amino diphenyl amines, more specifically amino diphenyl amines in which one phenyl nucleus is amino substituted and the other phenyl nucleus is alkyl substituted, possess outstanding inhibitor properties for the stated purpose. Compounds of this class having amino groups in the 2,4 position as shown in the following formula:

and in which R is an alkyl substituent group, preferably of branched chain type, are especially suitable. In the general formula, R. may, of' course, be any suitabie'alkyl residue such' as methyl, ethyl, propyl; butyl, amyl, etc.. Such;v compounds are characterized by high and en during activity in inhibiting the development of.

gums'in motor fuels, relatively high gasolinesolubility and satisfactory low water solubility-,mak- I ing them'particularly eii'ective inhibitors for use in the stated service. The data hereinbelowr resulting from extended study of these compounds, are illustrative of their inhibitive activity.

The test procedure followed that prescribed by the American Society for Testing Materials for indicating the gum stability of gasoline. This test (D525) is the conventional and well known oxygen bomb accelerated oxidation method in which a comparison 01. the induction periods obtained with respective uninhibited and inhibited samples provides a measure of the antioxidant activity of tested. compounds.

The compound employed as inhibitor in the test and falling within the class of compounds of this invention was 2,4 diamino, 4' tertiary amyl diphenyl amine. A

Gasoline sample Inhibitor g ggg Minutes A 154 A 0.52 Inga/100 c. c 210 B 200 B 0.48 Inga/100 c. c 300 C. 205 0 0.66 mgs./100 c. c 301 7 method of manufacture.

In the foregoing table the gasoline samples all comprise sweetened cracked distillate cut to motor fuel boiling range. As is customarily the case, samples taken at difierent' times or from difierent cracking units vary in their potential gum forming tendencies as evaluated by the conventional vinduction period criterion. This circumstance appears in the foregoing data.

2. A composition comprising gasoline normally tending to qxidine in storage and an alkyl 2,4 diamino diphenyl amine effective to inhibit said oxidation.

3. A composition comprising gasoline normally tending to oxidize in storage and an oxidation inhibiting proportion of a diphenyl amine in which one of the phenyl groups containing an alkyl substituent and the other phenyl group is amino substituted.

4. A composition comprising: gasoline normally tending to oxidize in storage and an oxidation inhibiting proportion of acompound from the class represented by the formula H v 2 E FDIC-NH:

wherein R represents an alkyl group.

5. A composition comprising gasoline .normally tending to oxidize in storage and an oxidation inhibiting proportion of a diphenyi amine in which one of the phenyl groups contains a branched chain alkyl substituent and the other phenyl group is amino substituted.

6. A composition comprising gasoline nor mally tending to oxidize in storage and a relatively small proportion of 4'. 2,4 diamino diphenyl amine.

EVERETT E. GILBERT.

tertiary amyl 

